1. Field of the Invention
The present invention relates to a substrate treatment method and a substrate treatment apparatus for treating a substrate such as a semiconductor wafer.
2. Description of Related Art
In a semiconductor device production process, a treatment liquid is supplied to a front surface of a substrate such as a semiconductor wafer to treat the front surface of the substrate with the treatment liquid.
A substrate treatment apparatus of a single substrate treatment type adapted to treat a single substrate at a time, for example, includes a spin chuck which generally horizontally holds the substrate and rotates the substrate, and a nozzle which supplies a treatment liquid to a front surface of the substrate rotated by the spin chuck. A chemical liquid is supplied to the substrate held by the spin chuck, and then pure water is supplied to the substrate, whereby the chemical liquid on the substrate is replaced with the pure water. Thereafter, a spin drying step is performed to remove the pure water from the substrate. In the spin drying step, the substrate is rotated at a higher rotation speed, so that pure water adhering to the substrate is spun off (dried). In this drying method, however, pure water entering gaps of a pattern formed on the front surface of the substrate is not properly spun off, but is liable to remain in the gaps of the pattern.
To cope with this, a substrate drying method is proposed in which, after the substrate is rinsed with the pure water, a normal-temperature organic solvent such as isopropyl alcohol (IPA) is supplied to the front surface of the substrate and the pure water entering the gaps of the minute pattern on the front surface of the substrate is replaced with the organic solvent for drying the front surface of the substrate (see, for example, U.S. Pat. No. 5,882,433A).